Sewing-machine attachment.



F. D. SWEET.

SEWING MACHINE ATIACHMENI. APPLICATION FILED AUG-9| I916.

Patented Sept. 18; 1917.

3 SHEETS-SHEET l.

F. 1). SWEET. v SEWING MACHINE ATTACHMENT.

APPLICATION FILED AUG-9| I916.

Patented Sept. 18, 1917.

3 SHEETSSHEET 2.

, -IIII?IEIIIIIIIIII l l I fizz/2221272 2 Mi WT I F. 0. SWEET.

SEWING MACHINE ATTACHMENT. APPLICATION mm AUG. 9, 1916.

1,240,384., I PatentedSept'lS, 1917.

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i me m FREDERICK 1). SWEET, or CLEVELAND, OI-IIO, ASSIGNOR r 0 THE SWEET-WEBSTER MANUFACTURING ooiviranv, oE CLEVELAND, onro.

SEWING-MACHINE ATTACHMENT.

Specification of Letters Patent. Patented Sept. 18, 1917;

Application filed August 9, 1916. Serial No. 113,347.

To all whom it may concern:

Be it known that I, FREDERICK D. SWEET, a citizen of the United States, residing at Cleveland, in the county of Cuyahoga and State of Ohio, have invented a certain new and useful Improvement in Sewing-Machine Attachments, of which the following is a full, clear, and exact description.

The object of this invention is to provide an inexpensive, easily operated, and highly efficient device adapted, to be readily attached to a sewing machine, and capable of so automatically moving a piece of cloth beneath the reciprocating needle of the sewing machine that there will be formed along each side of the line .at which the buttonhole is to be formed by subsequently slitting the cloth, a row of laterally extended stitches; and with which also the ends of the buttonhole may be finished by. stitches which extend laterally from the outer edge of one row of stitches to the outer-edge of the other rowof stitches.

Theinvention consists in the construction and combination of parts shown in the drawings, hereinafter described and definitely pointed out inthe appended claims.

In the drawings Figure 1 is a side view ofthe invention applied to a sewing machine. Fig. 2 is a plan view thereof. Fig. 3 is a planv'iew when the'cloth clamping lever has been removed. .Fig. 4 is a sectional side elevation. Fig. 5 is a sectional end view when the vibrating workholder is in one of its extremes of movement. Fig. ,6 is a similar view when the vibratingworkholder is in the other extreme of movement. Fig. 7 is a sectional plan view of certain parts of the device. Fig. 8 is a plan view partly broken. away of the rear end of the workholder. Fig. 9-is a plan view of the workholding foot; Fig. -10 is .a side view of the workholding*foot. Fig. 11 is a rear View of the rear end of the workholder. Fig. 12 is a sectional plan viewof the feed screw and associated mechanism. Fig. 13 is a sec tionalv side elevation of certain parts ofthe mechanism. Fig. 14: is a front elevation of themechanism when-applied to a sewing machine. I

Theattachmentincludes a subbase plate 10 which is preferably constructed to take the place in the sewing machine ofthe ordinary needle plate, whereby the attachment will be secured to the sewingmachine in proper working relation thereto. A base plate 12 is secured on the subbase by means which permit a slight lateral movement of the base plate. The means for so securing the base plate to the subbase and the purpose to be served by the lateral movement of the base plate will be presently explained.

On the base plate is a slide 15 movable between guides 13 forward and backward. Fixed to the slide and extending upward therefrom is the forked standard 20 in which a rock shaft 21 is mounted; There is secured to this shaft and extended rearward therefrom a substantially horizontal lever 22 in which is a slot 22*. The purpose of this slot is to embrace a laterally projecting stud on the vertically reciprocating needle bar B of the sewing machine whereby this lever will be rocked up and down in synchronism with the corresponding movements of the needle bar. Another arm 23 extends downward from this rock shaft and can ries a spring pawl 24 which will engage a ratchet 25. This ratchet is a disk which is pivoted on avertical stud 26 to the base 12, and has a plurality of upwardly projecting pins 25" for the spring pawl to en gage with. This ratchet is a part of a rotating member which also includes the gear disk 28 and the cam 29. It is obvious that as the lever is rocked up and down by the needle bar, the rotating member, of which the ratchet is a part, will be turned step by step, or more specifically, it will be turned through the arcual distance which corresponds with the distance between two adacent pins 2 "j on the ratchet every time the needle bar goes up, which it will be understood is at a time when the needle is clear of the work. I

A vibrating'workholder 40 is pivoted to the slide by means of a vertical stud 50 located near the front end of each. Along the side of the work holder arethe downturned flanges 452, which extend close to and are adapted to be engaged by the edges of the cam 29. This cam has an unequal number of equally spaced projections 29*;- in the presentcase five. When a projection 29 engages one of the downtur-ned flanges 42 of the vibrating workholder it will rock the same on its pivot to the right or left,

asthe case may be; and it may so rock to i be fed lengthwise of the buttonhole.

' tion in such proximity to the otherflange on they vibrating workhold vent such movement.

During each upward movement of the er as will preneedle the'cam will be turned so as towithdraw the projection on the cam from engagement with the downturned flange on the workholder and so as to cause another projection on said cam Tto .engagethe opposite flange of the workholder and thereby vibrate it-in the opposite direction. The path traveledby the rear end of the workholder in these vibratory movements thereof will beabout inch, and thismovement of course determines the length of thestitehslot; said slots being longer than the buttonholeto be worked, andof'a width sutii cient to permit the lateral vibration of the workholder while still keeping the slots 41 and 44 beneaththe needle. To insure that the work shall be firmly held down on the jaw 41 of the workholder a slotted clamping plate 46 isplaced beneath the jaw 44, which is the rear endof the lever 43 and the plate 46 is pivoted to the jaw 44 on a lateral axis so that it will have a' slight rocking movement that enables it to firmly graspthe workbetween it and the jaw of the lower workholder. The upwardly turned flanges 41 are formed on the sides of the'jaw 41, and the cloth goes over them and is therefore so held up that it is not likely to get under said work-holder. j

To facilitate the insertion of the work into the embrace of the workholder jaws, a bail 71 is pivoted to the front end of the workholder ;and-it is so shaped that when thejaw 44 is lifted by pressing down the front end of lever 43, the bailmay be swung over said lever end, and thereby thejaw will be held up. i

When the device in operation and the rear end of the 'workholder is vibrated back and forth so that the needle will go through the cloth at a point in close proximity to thelsubsequently to be cut slit Vor'buttonhole, or: through the cloth at a' slight distance back therefrom, it is necessary that the'work To produce this result a feed screw 51 is used. This lies below the base plate 12 and is-rotatably mounted at its front end in a bearing r bracket. l2 -fixedto and-projecting from I said base. This feed screw carriesa pinion 52 whose teeth engage the holes 28" in gear disk-'28 which' is a of the same rotating member ofa'vhich the cam and ratchet are carries at its front end av half nut 56 which' isintended-to engage: thev feed screw, and 'Wlll be automatically caused to engage it by a spring57 which is compressed between the rear ends. of said, levers.- W hen this nut is so engaging the feed I screw intermittent turning of thefeed screw- W-lll advance the slide the short distance. required between two successive buttonhole making stitches.- This screw induced fe'ed movement of the slide is rearward. 'iVhen it. has-progressed far enough, that istov-say, when it has prog ressed a distance slightly greater than the buttonhole,'the slide may move forwardto enable it to begin a newcycle of operation. In order-that this may be done quickly and easily, the operator takes hold of the rear ends of the nut carrying leversand presses them together in opposition to their spring, thereby releasing-the nut-from the feed screw, which permits the slide -to be pulled rearward to its starting point.

During this firstdescribed cycle of operations one side of the buttonhole is finished, let us say, for example, the rightside- This is because the workholder is vibrated from the line of the buttonhole to the right therefrom and back-and forth between-thesepositions. Tofinish the left sideof the butttonhole one shifts the position ofthe base'12 upon the subbase-l0. To enable this to be done the base has two laterally extended slots 60' through' it; and studs 61= fixed to-the sub base projectingnp throughthese slots. In the base likewise isa slot 62,- andthrough this slot passes an eccentric 63 that is pivoted to the snbbase, and has an operating lever 64 onits upper-end Byturningthis lever the eccentric will move the base upon the subbase to right or left a distance of approximately 1; inch, andjthis sets"; the mecha'nism' in readiness for forming the other side of the'buttonhole'. This eccentric base shifting mechanism is also useful in that it providesmeans for finishing the ends 7 of the buttonhole. When the end' of the buttonhole is reached the operator: may, when the needle goes up from the outer edge of one row of stitches, shift the base, w hich will result inthe descent-of the needle at point in line with-the outer edge of the other row-of stitches,that;-is to say, the stitch made-Will: be twice as long as the ordinary stitches. In making these long finishing stitches it is desirable that the *slide have no endwise feed movement. Therefore, in order to hold the half nuts out of engagement withthe feed screw so that the workman may have both hands freethe loop 7 0 is provided. This embraces both levers, but when near their pivots, it does not interfere with their movement such as will carry them into engagement with the feed screw. But by sliding said loop forward toward the ends of the levers when they are open, and it will hold them open, that is, will prevent the two half nuts from engaging the feed screw.

I'Iaviug described my invention, I claim: 1. In a buttonhole attachment for sewing machines, the combination of a base, a guided slide mounted thereon and movable forward and backward, and havinga downturned front end, a feed screw located below and mounted upon the base and passing forward through a hole in the downturned front end of the slide, apinion fixed to said feed screw, and means carried by the slide for disengaging said feed screw, and a r0- tating element lying above and mounted upon a vertical axis upon said base, and comprising as a lower member a disk in which are slots to receive the teeth of said pinion, a cam having an uneven number of cam projections, and a ratchet disk having double that number of upwardly projecting pins, a vibrating workholder pivoted on a vertical axis to said slide and having along its sides downturned edges adapted to be engaged by said cam projections, a standard fixed to said base, a bell crank lever pivoted thereto having a horizontal arm adapted to engage the reciprocating needle bar of the sewing machine and having also a do-wnturned arm and a spring pawl carried by said downturned arm to engage the pins on said ratchet disk.

2. In a buttonhole attachment for a sewing machine, the combination of a subbase adapted to be attached to the sewing machine,,a base mounted and movable laterally thereon, means to effect and prevent such lateral movement, a slide movably mounted upon said base and movable forward and backward thereon, a vibrating workholder pivoted to said slide on a vertical axis, a feed screw mounted on the base for operating said slide, a rotatable element mounted on a vertical axis upon the base and including a ratchet by which it is turned, a cam which engages the vibrating workholder to vibrate it back and forth, and a gear, an intermeshing gear fixed to the feed screw, a standard fixed to the base, a lever pivoted to said standard and carrying a pawl for engaging said ratchet, said lever being adapted to be engaged and operated by the reciprocating needle bar of the sewing machine.

3. In a buttonhole attachment for a sewing machine, the combination of a base, a slide mounted thereon and movable forward and backward and having a downturned front end, a feed screw located below and mounted upon the base and passing forward through a hole in the downturned front end of the slide, a pair of levers mounted on the downturned part of said slide and each car rying a half nut adapted to engage said feed screw or to be disengaged therefrom as required, means for holding said half nuts disengaged from said feed screw, a vibrating workholder pivoted on a vertical axis on said slide and extending rearward therefrom,said workholder having downturned flanges along its sides, a rotating element mounted on a vertical axis upon said base a and comprising a ratchet by which it may be turned, a. gear for turning the feed screw, and a cam having an uneven number of cam projections adapted to engage the downturned flanges of said vibrating workholder, a gear fixed to said feed screw and in mesh with the gear which is a part of said rotating element, a standard fixed to said base, a lever mounted thereon and adapted to be engaged and operated by the reciprocating needle bar of the sewing machine, and a pawl carried by said lever for actuating said ratchet.

L. In a buttonhole attachment for sewing machines, the combination of a base, a slide mounted thereon and movable forward and backward, a screw mounted upon the base, means carried by the slide for engaging and disengaging said screw, a vibrating work holder oivoted on a vertical axis on said slide ad acent the front end thereof and extending rearward therefrom, said workholder having downturned flanges along its sides, a rotating element mounted on a Vertical axis upon said base and comprising a ratchet by which it may be turned, a gear for turning the feed screw, and a cam lying between said downturned flanges and having an uneven number of cam projections adapted to engage said downturned flanges of the vibrating workholder, a gear fixed to said feed screw in mesh with the gear which is a part of said rotating element, a stand ard fixed to said base, a lever mounted on said standard and adapted to be engaged and operated by the reciprocating needle bar of a sewing machine, and a pawl carried by said lever for actuating said ratchet.

In testimony whereof, I hereunto affix my signature.

FREDERICK D. SWEET..

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Washington, D. 0. M v g 

